Hello @travelgirl I want to share history

Windsor Castle was originally built by William the Conqueror in the decade after the Norman conquest of 1066. William established a defensive ring of motte and bailey castles around London; each was a day's march – about 20 miles (32 km) – from the city and from the next castle, allowing for easy reinforcements in a crisis.Windsor Castle, one of this ring of fortifications, was strategically important because of its proximity to both the River Thames, a key medieval route into London, and Windsor Forest, a royal hunting preserve previously used by the Saxon kings. The nearby settlement of Clivore, or Clewer, was an old Saxon residence. The initial wooden castle consisted of a keep on the top of a man-made motte, or mound, protected by a small bailey wall, occupying a chalk inlier, or bluff, rising 100 ft (30 m) above the river.A second wooden bailey was constructed to the east of the keep, forming the later Upper Ward.By the end of the century, another bailey had been constructed to the west, creating the basic shape of the modern castle. In design, Windsor most closely resembled Arundel Castle, another powerful early Norman fortification, but the double bailey design was also found at Rockingham and Alnwick Castle.
Windsor was not initially used as a royal residence; the early Norman kings preferred to use the former palace of Edward the Confessor in the village of Old Windsor.The first king to use Windsor Castle as a residence was Henry I, who celebrated Whitsuntide at the castle in 1110 during a period of heightened insecurity.Henry's marriage to Adela, the daughter of Godfrey of Louvain, took place in the castle in 1121. During this period the keep suffered a substantial collapse – archaeological evidence shows that the southern side of the motte subsided by over 6 ft (2 m). Timber piles were driven in to support the motte and the old wooden keep was replaced with a new stone shell keep, with a probable gateway to the north-east and a new stone well. A chemise, or low protective wall, was subsequently added to the keep.
Henry II came to the throne in 1154 and built extensively at Windsor between 1165 and 1179. Henry replaced the wooden palisade surrounding the upper ward with a stone wall interspersed with square towers and built the first King's Gate.The first stone keep was suffering from subsidence, and cracks were beginning to appear in the stonework of the south side. Henry replaced the keep with another stone shell keep and chemise wall, but moved the walls in from the edge of the motte to relieve the pressure on the mound, and added massive foundations along the south side to provide additional support. Inside the castle Henry remodelled the royal accommodation.Bagshot Heath stone was used for most of the work, and stone from Bedfordshire for the internal buildings.